Set-Top Boxes used for cable television and satellite communications are proliferating and becoming a powerful hub for home entertainment. Such Set-Top Boxes, particularly digital Set-Top Boxes, not only facilitate the tuning of television programming but also are destined to provide pay per view, interactive television and Internet access to subscribers. Digital Set-Top Boxes are basically powerful computers with high-speed communications ability. However, such Set-Top Boxes, in order to become widely accepted and utilized, should be manufacturable at low cost and be easily repaired. In certain environments, it is advantageous to manufacture a Set-Top Box using multiple modular components which interact with one another. For example, a main computer circuit board can readily be manufactured as one assembly while a display mechanism and a Cable Modem can be manufactured as two other circuit boards, modules or sub-assemblies. This permits easy upgrade of the Cable Modem or the Main Circuit Board (Main Board) to add enhanced features at reasonable cost. Moreover, this facilitates the ability to utilize Cable Modems, Digital Subscriber Line (DSL) modems or satellite modems or other communication mechanisms in conjunction with a single standard Main Circuit Board.
In general, Cable Modems and other such communication devices communicate over the cable or other media via IP (Internet Protocol). Thus, an Internet Protocol (IP) address is assigned to the Cable Modem by the network administrator to facilitate network management and administrative functions. This may present difficulty, however, in providing a multiple circuit board modular approach to a Set-Top Box design in that the Main Board often needs to carry out actions requiring the IP address but may not have easy access to it since it is basically assigned to the Cable Modem. Thus, a mechanism is needed to communicate the IP address from the Cable Modem to the Main Circuit Board. It is also desirable to share a single display controlled by the Main Circuit Board to display not only information related generally to the operation of the Set-Top Box, but specifically to the Cable Modem. In each such case, the Main Circuit Board may require an IP address for the Cable Modem in order to utilize the common display.
While it is possible to hard wire memory locations or provide elaborate circuitry to provide the Main Circuit Board with the IP address residing in the Cable Modem, the interconnections required to accomplish this would increase the cost of the Set-Top Box, increase the wiring complexity and decrease reliability. It is therefore desirable to use conventional interconnection techniques such as Ethernet protocol or other protocol requiring minimal interconnection to couple the modules within the Set-Top Box together. Under these constraints, there remains the problem of how to communicate an IP address which may be assigned and reassigned by a network administrator from the Cable Modem to the Main Circuit Board.